Re: Sider power-supply repairs?

[mjmahon@aol.com (Michael J. Mahon)]

Ernest wrote:

>The power supply on my Sider II has a problem that looks easy enough to fix.
>There is a little white box, open at the top and filled with what looks like
>a white chalky ceramic substance. The markings on the little 3/4" by1/3" box
>are:
>
>CP-5-3  Dale 5W
>6.8Q 10% 8441

This is a wirewound resistor, 6.8 ohms, 5 watts.  It is probably a
"fusible resistor", meaning that it is meant to open like a fuse in
case of a prolonged overload.

>I'm not sure what this piece is but the solder that holds it in place has
>either fallen out or it melted. The area around it, on the board is
>blackened, as if it heated up but I'm not sure if it heated up because it
>was shorting (due to being loose) or if it's faulty.

It melted because the resistor heated up much more than normal.
This is most likely an indication of a more serious problem
"downstream" of the resistor, like a shorted semiconductor.

The bad news is that the power supply is not so easily fixed.  The
good news is that there is hope that the Profile was "retired" only
because of the power supply fault.  (And the hope is that the power
supply fault was not caused by a problem in the drive.  ;-)

>I plan to remove the faulty piece and replace it with a new one but I'm
>wondering if the solder that is used on a power supply board is different
>than the solder used on the Motherboard -ie, does the solder on a power
>supply need to have a higher melting point?

The solder is ordinary 60/40 solder.

Sounds like Wayne's offer is the best way to go...

-michael

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